President Bush has gotten strong backing from Britain and Spain for his ultimatum to Iraq to disarm or face invasion. Britain and Spain also are calling for international unity to deal with the Iraq crisis.

The summit on the Portuguese island of Terceira brought together President Bush with his two strongest allies in Europe, British Prime Minister Tony Blair and Spanish Prime Minister Jose Maria Aznar.

Mr. Bush declared that Monday will be a "moment of truth for the world" and the deadline for pursuing a new disarmament resolution at the United Nations.

Prime Minister Blair said the time has come for the U.N. Security Council to enforce its Resolution 1441, which demanded that Iraqi President Saddam Hussein immediately cooperate and destroy any weapons of mass destruction.

"So, now we've reached the point of decision," said Mr. Blair. "And we make a final appeal for there to be that strong, unified message on behalf of the international community that lays down a clear ultimatum to Saddam, that authorizes force, if he continues to defy the will of the whole of the international community set out in 1441."

Mr. Blair is particularly interested in a new U.N. resolution because of political pressures at home, where he faces threats of ministerial resignations and a revolt in his Labor Party over his hard-line on Iraq.

France poses the main obstacle to a new U.N. resolution. President Bush had earlier called for a U.N. vote on the proposed resolution, but he hinted that might not happen now because of France's threatened veto.

"I was the guy who said they ought to vote. And one country voted, at least showed their cards," said Mr. Bush. "It's an old Texas expression: "Show your cards." When you are playing poker. France showed their cards. After I said what I said they said they were going to veto anything that held Saddam to account. So cards have been played. And we'll just have to take an assessment after [Monday] to determine what that card meant."

Spanish Prime Minister Aznar appealed for unity in dealing with the Iraq crisis. "I would like to invite our friends, our allies, to leave aside any circumstantial differences, and to work together seriously for that commitment of democracy, freedom and peace, so that this becomes a commitment of us all," said Mr. Aznar.

The leaders issued a statement affirming that, if there is conflict in Iraq, the United Nations will have an important role in providing post-war humanitarian relief and political stability.